Friction Loss Calculator
Calculate pressure head loss due to friction in pipes using the Hazen-Williams equation
Calculate Friction Loss
Internal diameter of the pipe
Total length of the pipe
Volume of fluid flowing per unit time
Material affects the Hazen-Williams roughness coefficient (C)
Friction Loss Results
Head Loss
Pressure Loss
Formula used: HL = 10.67 × L × Q1.852 / (C1.852 × D4.87)
Material: PVC (Polyvinyl Chloride) (C = 150)
Pressure: Pd = HL × γ (γ = 9810 N/m³ for water)
Flow Analysis
Example Calculation
Water Supply System
Pipe: Copper, 250 mm diameter
Length: 10 meters
Flow Rate: 0.5 m³/s
Material Coefficient: C = 135 (Copper)
Calculation
HL = 10.67 × 10 × (0.5)1.852 / (1351.852 × 0.254.87)
HL = 10.67 × 10 × 0.365 / (4825.8 × 0.00128)
HL = 2.868 m of water
Pd = 2.868 × 9810 = 28,135 Pa = 0.28 bar
Material Comparison
Higher C values = lower friction losses
Friction Loss Tips
Smooth materials (PVC, fiberglass) have lower friction
Larger diameter pipes reduce friction losses
Keep velocities between 0.5-3.0 m/s for optimal design
Consider pipe aging - roughness increases over time
Understanding Friction Loss in Pipes
What is Friction Loss?
Friction loss is the reduction in pressure or energy that occurs when fluid flows through a pipe due to friction between the fluid and the internal pipe walls. This phenomenon affects the efficiency of pumping systems and determines the pressure available at outlet points.
Factors Affecting Friction Loss
- •Pipe Diameter: Smaller pipes have higher friction
- •Pipe Length: Longer pipes increase total friction loss
- •Flow Rate: Higher flow rates cause exponentially higher losses
- •Pipe Material: Rougher surfaces increase friction
Hazen-Williams Equation
HL = 10.67 × L × Q1.852 / (C1.852 × D4.87)
- HL: Friction head loss (meters of water)
- L: Pipe length (meters)
- Q: Volumetric flow rate (m³/s)
- C: Hazen-Williams roughness coefficient
- D: Internal pipe diameter (meters)
Pressure Loss
Pd = HL × γ
Where γ = 9810 N/m³ (specific weight of water at 20°C)
Applications
- • Water supply systems
- • HVAC piping design
- • Fire protection systems
- • Industrial process piping
- • Irrigation systems
Design Guidelines
- • Velocity: 0.5-3.0 m/s optimal
- • Use smooth pipes when possible
- • Minimize pipe length and fittings
- • Consider aging effects on roughness
- • Account for safety factors
Limitations
- • Water applications only
- • Turbulent flow assumption
- • Temperature effects not included
- • Empirical coefficients needed
- • Straight pipe sections only